SmartCart:
Initial Design Review
Pallavi Jain
Vivian Vasquez
Peter Nguyen
Deniz Kaplan
Product Definition
Function
Smartcart is an interactive touchscreen
display affixed to the handlebars of a
shopping cart which will allow users
to perform the following actions:
- Scan items to a checkout list
- Search for items
- Search for the aisle locations of items
- Obtain coupons for items
Application
Geared towards use by supermarkets, department stores, and other vendors that require the
use of a shopping cart. Shoppers can perform all searches, decreasing need to ask help from an
associate. An attached barcode scanner will be used to log items.
Product Definition (cont.)
Initial Specifications
- The RFID scanner should be able to detect the receivers on the entrances of
the aisles as soon as the device enters an aisle in order to relay the position of
the cart inside the store to the user (range and interference may pose problems
to this).
- A good GUI must be created in order to implement features like a readable
map/guide in order to guide users to products in the store. At the same time,
there must be ways to navigate the onboard software to access searching
functions and other onboard functions on the device.
Product Description
The user will be able to search for items on the display at the display’s home screen
from an item database. Transmitters placed along store aisles will send a signal to the
display whenever it is within 5 feet of the transmitter. This will allow us to map the aisle/area
the cart is in and let a user know on the display whether the product they seek is in that area
by querying a central database for the location of an item. This database will allow for the use
of targeted dynamic ads based on cart location and popular products. When the display has
been idle for a fixed amount of minutes, ads or coupons can be displayed. These may focus
on products that have been popular that week (can be determined by the number of
searches done on a product, a value stored in the database) or in that aisle. A button on the
ad will allow the user to return to the previous screen. Users can check whether there are
coupons for a product when they search for that product as well. If the item is in the cart,
coupons will automatically discount the price when an “Apply” button is pressed.
The cart will also have an affixed barcode scanner. A button on the display’s home
screen will allow a user to scan an item. The item will be added to a “checkout list”, which
can also be accessed through the home screen. Buttons will allow the user to clear the
“checkout list”, remove individual items, and check for coupons pertaining to the items in their
cart. A code can be sent to the cart at checkout when the cashier asks to checkout a cart’s
item list. If the cashier inputs that code, the central server should give the cashier the carts’
checkout list.
Product Development Effort
- Since development time is small and adding communication with a server into
the mix would greatly complicate and hinder development time, we will use
nonvolatile memory as storage for product information and maps for proof of
concept tests.
- Embedded OEM image scanners (i.e. barcode scanner) are costly, so we will
be using a handheld barcode scanner to accomplish logging a checkout list.
Team Composition and Responsibilities:
Pallavi Jain (Leader):
Vivian Vasquez:
Peter Nguyen:
Deniz Kaplan:
Power Management, Memory Interface
RFID
Display Subsystem
Barcode Scanner
High Level Block Diagram
RFID Tag
RFID Reader
Barcode Scanner
RS232
SPI/I2C
SDRAM
SD Card
LCD
Touchscreen
Components
LCD Touchscreen
○
○
Adafruit 2.8" (2.72'' x 1.97'' x 0.15'') 18-bit color TFT LCD ($40): resistive touch
panel, integrated display controller (already one on 2478), SPI and RGB interface,
320x240 res, 3.3V
(late entry suggested by prof.) NHD-3.5"-320240MF-ATXL#-CTP 24-bit color LCD
TFT ($44.50): capacitive touch panel (> resistive), no display controller, display
driver, touch panel I2C, 320x240 res, 3.3V
Barcode Scanner
○
EconoScan II Short Range CCD Barcode Scanner ($42.10): PS/2, RS232 and
USB interface, 3 oz., 6.10" x 3.07" x 0.63", 200 scans/sec
RFID Reader/Tags
○
SM130 Milfare Reader/Programmer Module ($29) with ISO14443A compatibilityUART and I2C interface, Milfare Classic 1k RFID tag ($3.95), PCB Antenna ($3)
SDRAM
○
Micron MT48LC128M4A2P-75 512Mb (~$20): 3.3V, 54-pin TSOP, synchronous
on positive clk edge, > 100microsec use delay
SD Card Connector/SD Card
○
Kyocera Series 5638 (~$5): Standard, surface and top mounted, any standard SD
card can be used (~$10)
Project Schedule
Milestone
System Level Design
Preliminary Design Review
Critical Design Review
Date
10/31
11/5
12/7
Task
Start Date
End Date
Person Responsible
Component Selection
10/22
10/31
Everyone
Bill of Materials
10/23
10/31
Everyone
Display Subsystem
10/26
10/31
Peter
Barcode Subsystem
10/26
10/31
Deniz
RFID Subsystem
10/26
10/31
Vivian
Power Management
10/26
10/31
Pallavi
Software Overview
10/28
10/31
Everyone
Detailed Design
11/1
11/5
Everyone
Verilog Sources
11/3
11/5
Peter, Deniz
Software Structure
11/4
11/5
Vivian, Pallavi
Design Implementation
11/7
12/7
Everyone
PCB
11/7
12/7
Peter
Final Schematic
11/8
12/7
Everyone
Final Bill of Materials
11/8
12/7
Everyone
Possible Features
Digital Scale
- SmartCart may also feature a digital scale with which customers can weigh
items which are not sold in fixed quantities, such as produce. This would be
located under the cart's basket compartment or beneath the leg hole closure for
customers to pull out.
The digital scale will only be implemented if an affordable model (current best
scale costs $400) or a suitable load cell can be found.
Technology/ IP Reuse
●
NXP LPC2478 processor
●
Econoscan II barcode scanner
●
Adafruit/NHD LCD touch panel
●
RFID Milfare Module
●
SDRAM
●
SD Card
Critical Elements
Display Subsystem
Without properly interfacing the microprocessor and touch display,
the project becomes useless. This includes creating a good GUI that
allows navigation and use of all the functions the software
implements and fitting it on a smaller than normal touchscreen.
RFID Transmitters and Receivers
Essential function of mapping cart to area/aisles becomes impossible
RFID reader is not suitable for proof of concept (LF: 1ft, HF: 3ft, UHF:
9.5 ft)